This application claims the benefit of Korean Application No. 2001-30081, filed May 30, 2001, in the Korean Industrial Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a disc cartridge to receive an information recording/reproducing medium such as a disc, and more particularly, to a disc cartridge which is highly resistant to dust.
2. Description of the Related Art
As shown in FIGS. 1 and 2, a known disc cartridge 10 receives a disc D to be used in an information recording/reproducing apparatus 100. The disc cartridge 10 includes upper and lower cases 11 and 12 spaced to receive the disc D. A holder 13 is inserted into and is combined with the upper and lower cases 11 and 12 and holds the disc D. A shutter 14 selectively opens and shuts apertures 11a and 12a, which are formed on the upper and lower cases 11 and 12, respectively, so that a pickup 130 of the information recording/reproducing apparatus 100 can access the disc D. Here, the reference numerals 11b and 12b denote receiving holes that are formed to be connected with the apertures 11a and 12a, so that a clamping domain D1 of the disc D can be clamped by a turntable 110 of the information recording/reproducing apparatus 100 and a damper 120. The receiving holes 11b and 12b and the apertures 11a and 12a are open or shut by opening or shutting the shutter 14. Reference numerals 11c and 12c denote locking grooves that are formed on the upper and lower cases 11 and 12, respectively, to hook a locking projection 13a that is formed on the holder 13. When combining the holder 13 with the cases 11 and 12, the locking projection 13a is elastically hooked into the locking grooves 11c and 12c. The locking projection 13a is slipped out of the locking grooves 11c and 12c by pressing and pulling a pressing unit 13b, which is extended past the locking projection 13a, so that the holder 13 is pulled from the locking grooves 11c and 12c. 
The information can be recorded on both sides of the disc D, as well as on a single side. For this reason, the disc cartridge 10 is formed so that the upper and lower cases 11 and 12 are symmetrical to each other, thereby allowing both sides of the disc D to be used. In other words, as shown in FIG. 2, the apertures 11a and 12a and the receiving holes 11b and 12b are identical and are formed symmetrically on the upper and lower cases 11 and 12, so that the pickup 130 can access one side of the disc D or the other side of the disc D by turning the cartridge 10 upside down.
The disc D is used while being stored in the cartridge 10 in order to protect the disc D from foreign substances such as dust. That is, a foreign substance such as dust can attach itself to the surface of the disc D, which can obstruct accurate signal processing during recording and reproducing operations, especially in the case of a high-density disc. However, it is inevitable that dust will enter the cartridge 10 through the upper and lower apertures 11a and 12a, because the shutter 14 must be open for access of the pickup 130 during information recording or reproducing operations, as described above. Even though an aperture 11a or 12a of the unused side of the disc D is not accessed by the pickup 130, dust nevertheless passes through the unused aperture.
To solve the above problems, it is an object of the present invention to provide an improved disc cartridge which is highly resistant to dust.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Accordingly, to achieve the above and other objects, there is provided a disc cartridge including a case to form a space in which a disc is received and a shutter to selectively open and shut an aperture formed on the case, wherein the aperture is formed on only one side of the case.